Almond emulsin peptide: N-glycosidase (PNGase) hydrolyzes the Beta-aspartylglycosylamine linkage in glycopeptides and som glycoproteins, releasing intact oligosaccharide chains and carbohydrate-free peptides and proteins. PNGase will release oligosaccharide moieties from both a high-mannose ovalbumin octaglycopeptide and a series of biantennary complex glycopeptides ranging from three to eleven amino acids in length isolated from IgM. Additional glycopeptide substrates of the tri- and tetraantennary tye will be isolated from fetuin and Alphal-acid glycoprotein in order to define the specificity of the enzyme. Dansyl-complex glycopeptide derivatives suitable for detection of PNGase- or endoglycosidase-type enzymes in mammalian tissues will be developed. Detection of these enzymes will explain the many oligosaccharide fragments released in urine or accumulated in tissues in human disease involving a deficiency of carbohydrate hydrolase. PNGase-type enzymes will be used to release intact complex oligosaccharide chains from bioactive glycopeptides and glycoproteins. The physical properties of native and carbohydrate-free (glyco) proteins will be investigated in order to study the function of the carbohydrate in maintaining the native state.